The equivalent 1 MeV neutron fluence Φeq can be calculated multiplying the proton fluence (Φp) by the hardness factor k:
For a 24 GeV/c proton beam (IRRAD) k = 0.58 (best estimate from experimental measurements: https://cds.cern.ch/record/2162852
Proton of momentum ≥GeV/c and pions ≥300 MeV/c deposit energy at a rate of ~2 MeV·cm2/g in practically all target materials (minimum ionizing energy loss rate). Under these conditions (valid for the CERN PS protons of IRRAD and positive pions at PSI) a good estimation of the absorbed dose [Gy] can be done using:
Dose [Gy] = 1.602 × 10-10 × (dE/dx)min [MeV·cm2/g] × Φp[cm-2]
Where Φp is the proton (or pion) fluence [cm-2] and (dE/dx)min are the values listed in this table [MeV·cm2/g] for various materials and compounds.
For further information please read this publicaton https://doi.org/10.1109/TNS.2018.2829864
Please, find an online converter in this link